Ferromagnetism in Bi2Se3:Mn Epitaxial Layers

Published

August 30, 2013

Author(s)

H.J. von Bardeleben, J.L. Cantin, D. M. Zhang, A. Richardella, D. W. Rench, N. Samarth, Julie Borchers

Abstract

The magnetism in approximatley}1at% Mn doped nanometric Bi₂Se₃ epitaxial layers has been studied by ferromagnetic resonance (FMR), magnetometry and polarized neutron reflectivity (PNR) measurements. The FMR results reveal the formation of an intrinsic homogeneous ferromagnetic bulk phase as confirmed by the PNR measurements. Its critical temperature is low, Tc≅6K. The FMR measurements at T=4.2K show a single uniform mode spectrum with a strong uniaxial in-plane/out-of-plane symmetry. The uniaxial anisotropy field at T=4K is H_aapproximatley} -2500 Oe, corresponding to a uniaxial anisotropy constant of -9x10³ erg/cm³. The easy axis of magnetization is oriented in the film plane for temperatures between 4K and Tc. For a rotation of the applied magnetic field in the film plane we observe a weak six-fold anisotropy. As the films are highly n-type conductive, conduction electron mediated ferromagnetism in this (very) diluted magnetic semiconductor is considered as the most probable origin of the FM phase formation. Previously evidenced ferromagnetic surface states with ordering temperatures above 40K are not detected by these techniques.

Citation

Physical Review B

Volume

88

Issue

7

Pub Type

Journals

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Keywords

topological insulators, ferromagnetic resonance, surface magnetization, polarized neutron reflectivity

Citation

von Bardeleben, H. , Cantin, J. , Zhang, D. , Richardella, A. , Rench, D. , Samarth, N. and Borchers, J. (2013), Ferromagnetism in Bi₂Se₃:Mn Epitaxial Layers, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=914353 (Accessed December 26, 2024)